Method of producing copper mattes, white-metal, and blister-copper in a single furnace.



No. 794,272. PATENTED JULY 11, 1905. R. BAGGALEY.

METHOD 0E PEODUGING COPPER MATTES, WHITE METAL,

AND BLISTER COPPER INA SINGLE FURNAGE.

A'PPLIOATION EILED APE.13.1904.

@uw G WITNESSES No. 794.272. PATENTED JULY 11, 1905.

R. BAGGALY.

METHOD 0F PRODU G COPPE TI'ES, WHITE METAL, AND BLISTE PPBR IN NGLEFURNAGE.

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AAAAAAAA IQN FILED APR.13.1904.

l l i i CW o. 552% 4 wff@ No. 794.272. 111T11N'11111 JULY' 11, 1905.

11. BAGGALBY. METHOD o1" PRODUGING COPPER MATTES, WHITE METAL,

AND BLISTER COPPER IN A SINGLE FURNAGE.

APPLIQATION FILED 11.211.13.1904.

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wrrnEssE-s v 1% No. 794.272. PATBNTED JULY 11, 1905. R. BAGGALEY.

METHOD OP PRODUGING COPPER MATTES, WHITE METAL, AND BLISTER COPPER IN ASINGLE PURNAGE.

APPLIATION FILED APR.13.1904.

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METHOD 0F PRODUCING COPPER MATTES, WHITE-METAL, AND BLISTER-COPPER lN ASINGLE FURNACE.

SPECIFICATION forming part of Letters Patent No. 794,272, dated July 11,1905.

Application filed April I3, 1904:. Serial No. 202,928.

Be it known that I, RALPH BAGGALEY, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a Method of ProducingCopper Mattes, White- Metal, and Blister-Copper in a Single Furnace, ofwhich the following is a specification, reference being had to theaccompanying drawings, in which- Figure 1 is a vertical longitudinalsection of a converter suitable for the practice of my invention. If ig.2 is a vertical cross-section on the line II II of Fig. l. Fig. 3 is aside elevation7 partly in vertical section, of a stationary furnacewhich may also be employed. F ig. 4 is a vertical cross-section on theline IV IV of Fig. 3.

h/Iy invention provides means by which copper matte and, if desired,white-metal and blister-copper can be produced direct from the ore in asingle furnace, and thus make it possible to dispense with the expensiveand wasteful practico which has obtained heretofore, in which whenslnelting silicious ores the ores are water-concentrated to remove alarge percentage of the silica, then calcincd, smelted in ablast-furnace with coke to produce a matte, and the matte then blown ina converter. The losses involved in every step of the former practiceare very great, and the process has been expensive and unsatisfactory.

In the practice of my invention I use a combined melting and convertingvessel,

which may be either the tipping converter shown in Figs. i and Z or astationary furnace, as in Figs. 3 and 4L. The converter is provided withtwyers 2 2 for introducing an air-blast and with burners 3 3, arrangedon opposite sides of the converter, to discharge Vflames downwardly andso located that the flames will impinge directly on the surface of thebath. In this manner I deliver heat to the desired points on the surfaceof the bath accompanied with the requisite supply of oxygen to producethe greatest efiiciency in the combustion. The converter should not havethin water-jackets exposed to the bath, since that would chill the bath,and I therefore prefer to employ a converter or converting-furnace withthick walls, preferably made of slabs or blocks of east metal, whichwill resist the intense heats produced during the process withoutchilling the molten charge.

In practicing the invention I introduce into the converter a firstcharge of material whose distinctive feature is freedom from compoundslikely to produce light silica slags. I prefer to use for the iirstcharge a matte in congealed form, or in the absence of this pyrrhotiteores and certain sulfid ores maybe successfully employed. These ores arehigh in fuel values-'that is, high in sulfur, iron, and other elementswhose oxidation by the air-blast will produce a high temperature in thebath. I-Iaving introduced this charge into the converter, I direct theflamejets from the burners upon it and melt it,

thus forming a molten bath sufiicient to' cover the twyers. .In thisoperation I prefer to use no coke or charcoal, because when coke orcharcoal is fed with the ores and fluxes in a solid heavy column it willhave its foundation solidly planted over the entire area of thefurnace-betteln and will afford no space for an accumulation of moltenmatte except in the interstices of the mass, where it is not readilyacted upon by the converting-blast. It also tends to become choked withslag, which in that position is chilled by the air-blast, for althoughair blown into matte produces an intense heat air blown. into slag,because of the absence of fuel values, produces a chilling effect,peculiarly aggravated when the slag is mingled with ore. Moreover, evenif the coke or charcoal is detached fromv the bottom through theagitation produced by the blast the lumps become enveloped in a coatingof slag, which seals them from contact with vthe air-blast7 renders themincombustible, and in this condition they remain as an infusibleobstruction floating on the molten bath that seriously interferes withthe submerging of the ore charge into the clean matte below. Thereforewhen solid fuel is used for the initial melting I discontinue it andremove it as soon as possible by tilting the converter or if astationary furnace is used by scraping it out into the forehearth, thusproviding a bath of clean matte in which to commence the dissolving ofthe ore.

After forming a molten body of clean lowgrade matte by melting it in theconverter in sufficient volume to cover the convertingtwyers I shut theburners and start the converting-twyers into action, and thereafter feedore to the bath preferably continuously and in small and regularquantities. By this I mean that each individual charge of cold raw orethus fed shall constitute only a very small proportion relatively to theentire body of the molten matte contained in the converter. As soon asthis process is started two distinct operations will be in progress atthe same time-first, the existing body of molten low-grade matte will berapidly oxidized and an intense white heat will be developed owing tothe large volume of blast delivered through the converting-twyers gsecond, at the same time new supplies of fresh ore will be constantlydropping into the bath in small quantities at a time, and these will besubjected quickly to the following processes: Any contained moisturewill be expelled, they will be fractured through the action of theexcessive heat, their temperature will be raised to approximately thatof the molten bath, they will be melted, and in the molten form theywill join the remainder of the bath and will also be subjected tooxidation. During this process the slag is withdrawn from time to timeby tipping the converter. The addition of new ore will increase thevolume of the bath. At the same time the rapid oxidation will reduce itsvolume.

It will be desirable to take occasional test samples in order todetermine the mineral contents of the matte and to stop the orefeed fromtime to time in order to enrich the matte up to any desired degree,inasmuch as the continuous feeding of a comparatively low grade orecharge will have the effect of reducing the percentage of mineralcontents. At this stage of the process the converter will be operatingwith a continuous feeding of ore, with twyers in full operation, withoutcarbonaceous fuel, and with the auxiliary heat of the burners shut off.In other words, at this point in the process and thenceforth until thecompletion of one run I depend exclusively for the heats that enable meto perform a continuous melting process as long as I may desire to do soupon the combustion of iron, sulfur, arsenic, manganese, selenium,tellurium, and any other heat-producing elements or compounds usuallyfound in ores. I am enabled vby'this means to eliminate with successobjectionable impurities which cause so much trouble in other processesand to produce and continuouslyy maintain a very high temperature.

If exceptionally refractory ores are under treatment, the heats ofconversion may be supplemented and augmented at will and to any desiredextent through the addition of the auxiliary heat-flames. During theprogress of the conversion the variety of ore fed to the convertershould be determined by the condition of the bath, and it is importantto keep the bath as free from floating slag as possible in order thatthe entering ore may be unobstructed in its union with the moltenmatter. Silicious ores of any description are added when flux is needed,and when fuel is needed ores rich in fuel values-such as the iron sulfidores of the Butte district, which are usually low in mineral valuesareutilized. Such low-value ores are at present incapable of being used,and for this reason millions of tons thereof are now neglected in Butteand in Arizona copper-mines. In like manner pyrrhotite ores, which areinvariably low in values, and all the low-grade sulfid as well asarsenic ores can be profitably used because of their greatheat-producing properties. When silica flux is needed in order toseparate the oxidized iron from the bath, all the quartz, gold, silver,and other ores associated with a quartz gangue that are now treated instamp-mills or arastras, Chilean `mills, and other processes of waterconcentration with high percentage of loss can be used, and the mineralcontents can thus be recovered almost without loss. In like manner allthe Butte ores, either those whose distinctive value is silver and whosegangue is usually tertiary granite, quartz, rhodocrosite, cc., as wellas those Butte ores whose dis- IDO tinctive value is copper and whosegangue is usually tertiary granite, porphyry, rhyolite,4

aplite, &c., may be thus used, inasmuch as the gangue of all of these isdistinctly acid or silicious. My process is capable 0f recovering valuesfrom all ores of copper, gold, silver, nickel, and cobalt. Thus all thecarbonates, oxids, cuprite, bornite, Lake Superior and Arizona virgincopper and scrap', also concentrates, mattes, &c., may be added to thebath at will and become dissolved and form a part of the molten bathwith much greater economy in treatment costs and with much less minerallosses than when treated by any other known method. The best results areobtained by alternating the ore charges between ores rich in fuel andores rich in flu and values.

When the matte has been enriched to forty per cent. copper or over, Idiscontinue at that time the feeding of such ores as would lower thegrade of the matte and continue to blow the charge in the sameconverter, using silica ores as a flux until it is brought to the gradeof white-metal and thereafter to blistercopper, when it may be withdrawnand cast into pigs or slabs, or when it has reached the grade ofwhite-metal I may transfer 1t to a finishing-converter and thentransform it to I blister-copper as a means of augmenting the IIO IIS

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producing capacity of the plant. The feeding of all kinds of ore must bestopped when the grade of white-metal has been reached.

In my process Without previous concentration of any kind I melt the oresquickly into a low-grade matte and thereafter, through the medium of theconverting-twyers, I enrich such low-grade matte into a high-grade matteof any degree desired.

In melting an ore charge that by assay averages four per cent. of copperit has been my experience that the melted matte will approximate eightper cent. An ore charge that averages five per cent of copper Will thusyield usually a matte of nine per cent. An ore charge that will averageten .per cent. of copper Will usually yield a matte that will. assayfourteen. per cent. In other Words, I have found that the mere meltingof the ore has the effect of enriching it approximately four per cent.Withoutmuch regard to its initial average mineral contents.

Where my invention is operated, say, for instance, with an ore chargethat averages six per cent. of copper, the 'fusion of this ore willproduce a resultant matte approximating ten per cent of copper. Vhen theconverting-tvvyers begin to act upon a matte like this, I thenceforthdepend alone upon the heats derivable from the oxidation of theimpurities in order to continue the smelting operations. I can readilydo this, because at this point the matte Will contain ninety per cent.of oxidizable impurities that are depended upon to supply heat, Whereasthe ordinary converting process as at present successfully conductedeven at the commencement has but one-half this percentage of oxidizableimpurities for a heat-supply, or it may have even less.

The heats utilized in this process, as before stated, are very great,and for this reason I can utilize a much larger proportion of silica andproduce a much lighter and more fluid silicate of iron slag than ispossible in present smelter practice, and hence the globules of mattecan separate by gravity more readily from my slags than from others. Iam enabled in this manner to discharge as slag ninety per cent. of theentire tonnage treated Without the usual losses incident to Waterconcentration, to calcining, and to slovv smelting and with less thanone-half the loss of metal in foul slags that are inseparable frompresent practice. After this Worthless tonnage has thus beenautomatically discharged from my furnace and after my matte has beenenriched through the action of the converting-twyers up to any pointthat I may desire, but preferably up to a point Where the matte Willcorrespond to that usually supplied to Bessemer converters, or, say, upto from forty-'live .to sixty per cent., I then feed the converter againWith ores containing values, but exclusively on such oresas run veryhigh in silica-say, 'for instance, eighty per cent. or over. By thismeans I perform in the furnace with ores containing values which Iseparate and recover the Work heretofore done in the first stage of theconverting process through. the destruction of the silica lin ing. Whenthe requisite volume of mineral has been thus concentrated in the vesseland the iron has been separated from the bath through the addition ofsilicious ores and when this material has been withdrawn from the vesselin the form of silicate of iron slag, the feeding of ores of everynature and. kind .is stopped at the point where the bath consists ofwhite-metal. It may then be transferred to a finishing-converter, asbefore stated, or it may be ca'rried to blister-copper in the original.vessel merely by continuing the action of the converting-twyers untilthe desired point has been reached.. Should the action of theconverting-blast have an undue chilling effect on the metals,particularly toward the Afinal stage of the process, such chillingeffect may be effectually counteracted and conquered by again startingthe auxiliary heat-jets into operation.

Many unsuccessful attempts have been made in the past to add silica tothe charge as a means of separating the iron otherwise than by theexpensive mode of supplying it from the converter-lining. In one ofthese unsuccessful attempts, which is typical of all the others, it wassought to deliver the requisite quantity of silica into the converter inthe form of finely-powdered quartz sand by blowing it with the blastthrough the tWyers. The results may be briefly summed up as follows:

First. In order to satisfy the iron, about one-half as much quartz sandWas required as the amount of copper contained in the matte. I-Ience foreach ten tons of copper it Would be necessary to deliver into theconverter about Afi ve tons of quartz sand.

Second. The quartz sand quickly cut out and destroyed the twyers.

Third. The chilling effect of this large amount of cold solid materialsupplemented and greatly aggravated the chilling effects of the blastitself,

Fourth. Matte isvof one specific gravity, silicate-of-iron slag is ofanother and lighter specific gravity, While pure silica is of anotherand of a very much lighter specific gravity. As a result just as soon asany slag Was formed the contents of the converter separated into threedistinct layers. The matte occupied the bottom portion of the converter,the silicate-of-iron slag floated on it, and the pure silica Vfloated onthe slag layer. The tWo elemen ts, therefore-the iron in the matte andthe pure silica-Were liepelessly separated and the desired union Wasimpossible.

Fifth. In making careful examination of ICO IIO

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the mass that had thus chilled in the converter it was found that eachseparate particle of quartz sand that had been driven into the converterby the blast was enveloped in a protecting layer of chilled infusiblesilicateof-iron slag and that it was thus protected by a non-conductingcoating against possible attack by the iron', even had they been inactual contact, which they were not. All like attempts to introducelumps of quart?l into the bath have also resulted in failure.

The experience above recited will not be repeated in my process, and thesilica, slag, and matte will not separate into distinct layers, for thefollowing reasons: First, I use highly-silicious ore to supply thesilica, and the specific gravity of the ore is greater than pure silicaor silicate of iron', second, the heats produced in this furnace, aidedwhen desired by the llames from the burners, are so great that the slagitself will overcome the chill of the silica to heat it, and finally toliquefy it so long as the feeding of ore is continued, third, when it isdesired to add the silica ore I remove the top layer of low-grade slag,so that the silica ore will be instantly ilrunersed in a clean bath ofvery hot molten matte, where it will be quickly heated, fused, anddissolved.

At the conclusion of the operation after the charge has been finali ywithdrawn the converter is again charged with ore and theA process isrepeated 3 but at this time the percentage of fuel required to melt thecharge will be materially lessened because of the heated condition ofthe converter-walls.

Irl-order to expedite the process and to save labor, which in miningdistricts is very costly, I prefer to provide charging mechanism, bywhich the ore can be delivered automatically to the converter orfurnace.

Where the stationary furnace (shown in Figs. 3 and 4) is employed inpracticingr my invention, I proceed as above described, except thatinstead of discharging the slag and copper by tipping the apparatus Iwithdraw them through a slag-spout and through a metal tap-hole,respectively. In the drawings, 2 represents the melting and convertingchamber of the furnace, built, preferably, of thick cast metal slabs orblocks, which will resist the high temperature and will retain the heatin the furnace without abstracting it, as a thin water-jacket would do.3 3 are the twyers. 4 4L are the oil-burners; 5 5, the charging-opening;6, the outlet for metal or matte, and 7 the outlet for slag. 8 is abotting device for the tap-hole 6. It has an arm 9, provided with a cup10, adapted to hold a plug of clay or like material, which may be swungby a hand-wheel 11 to bring the plug against the tap-hole, where it isheld by a locking-lever 12. The slag-tap is preferably made adjustableto any desired extent of opening by two vertically-sliding water-cooledsections 13 14, the lower one of which carries the slag-spout, and whichare moved by powerful mechanism, consisting of racks 16 and pinions 17.By separating them a large opening is afforded for insertion of a rabblewhen it becomes necessary to skim the slag, which is formed in greatvolume during the operation. The slag-spout may be lowered to any extentto suit the varying level of the bath, and thus to make possible theremoval of the slag under all conditions of the furnace.

I utilize water-cooled pieces in the adjustable slag-spout,notwithstanding the chilling and therefore injurious effect that theyexert on the contents of the furnace, because the pieces are small inproportion. to the size of the bath andtheir chilling effect is notgreat, and by water-cooling them I prevent the internal skull or liningof chilled matte or slag from forming such a tough bond as would preventits fracture when the powerful mechanism is utilized in opening thespout for the removal of slag.

When the slag and matte or copper are Withdrawn, it is necessary to shutoff the blast, and for this purpose I provide the twyers with suitableplugging devices.

lhe upper part of the chamber 2 is contracted, as at 18, so as to form acomparatively narrow throat or passage connecting it with the uppercharging portion. The walls preferably slope inwardly, and the chamberis preferably made wide and much wider at the bottom than at the throat.The heat is thus retained to any desired extent, and the splashing ofthe liquid matte or slag by the blast at the middle of the bath takesplace at a distance from the side walls, which are therefore not apt tobe incrusted thereby. The throat may be rendered variable in width byproviding one or more sliding sections 19, moved inwardly and held bylevers 20. The appropriate adjustment of these sections will. make iteasy to maintain the heat of the furnace at the proper degree.

The furnace-bottom 21. is concave and is lined withV anon-heat-conducting lining of magnesite brick or the like, which willnot be destroyed by reaction with the iron oxid produced by oxidation ofthe matte. At the final stage of the process, when the matte has reachedapproximately the grade of seventy-l six per cent. of copper, gold, andsilver and twenty per cent. of sulfur, the charge being lessened involume rests mainly or entirely within the concavity of the bottom,which, being a very poor conductor of heat, has the effect of holding itin liquid state during final treatment with the blast from the twyers,so

that at the termination of the process it may be tapped. Should itbecome unduly chilled,

its heat may be restored and maintained at! any desired temperature bythe auxiliary heat-flames.

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My process of recovering values from various ores and 1n reducing themto actual metal may be practiced in districts far removed fromtransportation by providing a suitable furnace or converter, as hereindescribed, means for providing a converting blast and a slag-boiler, asdescribed in my patent application, Serial No. 203,486, liled April 16,1904.

By the term low-grade matte used in this specification and claims I meanmatte containing a less percentage of metal values and a higherpercentage of fuel constitu en tsiron, sulfur, and the like-than isemployed in present converter practice. Thus in a modern text-book it isstated that at the present time in America no copper material isregularly bessemerized, excepting "matte containing over forty-live percent. of metal values, and that a matte containing from forty-'live tofifty per cent. is considered low grade when referring to the Bessemerprocess as usually carried out in America. As compared with thispractice I provide a body ofi matte of lower grade than can be used inpresent converter practice without too rapid corrosion of the lining andemploy it as a bath to which are made successive additions ofvalue-bearing ore relatively high in silica for the purpose of enrichingthe bath withv the contained values and lluxing the iron of the matte.The matte which I prefer to use for this purpose contains from six totwelve per cent. of metal values, since such matte can be producedreadily and with economy by melting sullid ores 5 but it may contain aconsiderably higher percentage of such values.

Within the scope of my invention the process and apparatus may bemodilied, since What I claim isy l. The method herein described ofproducing matte, white-metal or blister-copper in a single vessel orchamber, which consists in producing a bath by melting matte-makingmaterial in such vessel or chamber producing thereby a low-grade matte,removing slag and adding to the molten bath from time to time ore insmall quantities at a time, namely in less quantities than the moltenbath., blowing air through the bath and by the heat thereby developedfusing and lluXing such additions of ore; substantially as described.

2. The method herein described of produc? ing matte, white-metal orblister-copper in a single vessel or chamber, which consists inproducing a bath by melting matte-making material in such vessel orchamber with flame applied from above producing thereby a low-gradematte, adding to the molten bath from time to time ore .in small quantities at a time, namely in less quantities than the molten bath, blowingair through the bath, and by the heat thereby developed fusing andluXing such additions oi ore g substantially as described.

3. The method herein described of producing matte, white-metal orblister-copper, which consists in Yforming a bath of lowgrade matte in avessel or chamber, adding 'from time to time ore in small quantities ata time, namely in less quantities than the molten bath, blowing airthrough the bath, and by the heat thereby developed fusing suchadditions of ore, and collecting the enriched and concentrated matte ormetal at the vfinal stage of the process in a non-heatconducting cavityin said chamber; substantially as described.

4L. The method herein described which consists in forming a molten bathol lowgrade matte, blowing air thereinto, adding ore relatively high insilica in small quantities at a time, namely in less quantities than themolten bath, and also adding charges of ore or matte high in fu elvalues in. like manner, and applying the heat ol a flame above thesurface of the bath.; substantially as described.

The method herein described of predileing copper matte or copper, whichconsists in Aforming a bath. of molten low-grade matte, blowing airtherein to, feeding to the bath ore in small quantities at a time,namely, in less quantities than the molten bath, and constricting theoutlet of the resultant gases from the chamber; substantially asdescribed.

6. The method herein described of producing copper matte or copper,which consists in 'forming a bath of molten l.owgrade matte, blowing airthereinto, feeding to the bath ore in small quantities at a time,namely, in less quantities than the molten bath, constricting the outletol the resultant gases 'from the chamber, and varying the extent ofconstriction oi' the outlet conformably to the heat requirements of thebath g substantially as described.

7. The method herein described which consists in forming a molten bathof lowgrade matte by melting a sulhd ore without otherwise materiallyincreasing its percentage of metal valuesblowing air thereinto, andadding silicious value-bearing ores to flux the iron of the matte and toadd values thereto; substantially as described.

In testimony whereof I have hereunto set my hand.

RALPH BAGGALEY.

Witnesses J H. REED, THOMAS W. BAKEWELL.

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